Home communication devices, such as gateways, modems, settop boxes and phone devices, often include a backup battery in order to operate under a backup power source when the main power source is interrupted (e.g., electric utility power outage). The backup battery in these devices may be rechargeable, and the devices may include a charging system for maintaining the condition of the backup battery. However, there are a number of conditions associated with maintaining the performance (i.e., full charge level) of the battery. For instance, in order to extend battery life, the battery is never fully charged because too much heat will be generated and battery lifetime may be shortened. As a result, the battery is only charged to, and maintained at, between 70% and 90% of full capacity.
However, a readout showing the actual battery charge condition may be confusing to the user if the battery is shown at 70%, even if it is not being further charged or showing 90% when the battery is fully charged. Cell phone batteries may operate under similar principles. However, cell phone batteries represent the primary source of power and are more likely to be continually charged and discharged rather than operating as a backup system. The cell phone also does not self charge. The cell phone typically requires a user to plug in to a charger. Further, unlike the cell phone battery charging process, the backup battery in a home communications device may be recharged under a variety of conditions in order to most optimally maintain best performance for providing a specified time period of backup operational phone service (e.g., up to eight hours of service). As a result, simple scaling of the battery condition for the user display is not practical and does not address potential user confusion issues regarding battery charge levels. The present invention tries to provide a sensible translation of the charging conditions used in the product with the charging condition readout to the user.